Typically, a substrate-to-substrate electrical connector includes a plug connector and a receptacle connector. The plug connector and the receptacle connector are mounted on respective substrates thereof and fitted with each other to connect the substrates to each other. The plug connector includes at least a plug contact and a block. The receptacle connector includes at least a receptacle contact and a housing. In some cases, fixtures are used for the connectors, as necessary.
Below are shown documents regarding an electrical connector for a substrate-to-substrate connection which the applicant has previously proposed. The documents are as follows: Patent Document 1 (JP Patent Appl. Publ. No. 2009-266629), Patent Document 2 (JP Patent Appl. Publ., No, 2009-517802), Patent Document 3 (JP Patent Appl. Publ. No, 2010-198996), and Patent Document 4 (JP Patent Appl. No. 2011-107743).
[Patent Document 1]
    JP Patent Appl. Publ. No. 2009-266629[Patent Document 2]    JP Patent Appl. Publ. No. 2009-517802[Patent Document 3]    JP Patent Appl. Publ. No. 2010-198996[Patent Document 4]    JP Patent Appl. No. 2011-107743